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A Guide to Truck Classifications

Jan 18, 2022 ·

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There are many different heavy-duty and diesel vehicles on the road today. In the United States, truck classification systems are used to help signify what large vehicles are built to do.

Those working in the automotive and diesel industries are familiar with these systems. Instead of simply seeing a truck driving down the street, they know how to sort these vehicles into their proper classes and designations.

There are many reasons why these classification systems are important. Keep reading to find out more about them, along with how different vehicles are classified.

Gross Vehicle Weight Rating

Vehicles in the U.S. are classified by gross vehicle weight rating (GVWR) on a scale of 1 through 9, with 9 being the largest possible GVWR.

Truck classification looks at the GVWR, which is the maximum truck weight plus the amount it can carry fully loaded. This includes:

  • Passengers
  • Fuel
  • Products/cargo
  • Accessories like the trailer tongue

These classifications are important for safety and commercial designation when vehicles are registered. They also can help determine whether a truck should stop at a weigh station, how long a truck is able to operate and what kind of permits are required for someone to drive it.

Certain signs and permits might need to be identified when hauling oversize or overweight equipment. The Department of Transportation (DOT) also sets number regulations. If a vehicle weighs more than 10,001 pounds, there must be a DOT number on both sides.

Knowing the correct truck classification can also help technicians prepare to perform maintenance on a vehicle. A shop might need to set aside a certain amount of space and prepare the work area depending on which class the vehicle falls under.

Drivers need specific licenses to operate vehicles, including a commercial driver’s license (CDL). CDLs are divided into classes A, B and C. One factor that determines which license is required could be the GVWR, while another could be whether the vehicle is designed or used to carry more than 10 passengers including the driver.

Truck Classifications

The categories for classifying vehicles and trucks range from Class 1 to Class 9:

Classes 1-3: light-duty

The first three classes encompass non-commercial vehicles. These can include SUVs, minivans and pickup trucks. These are considered light-duty vehicles.

Classes 4-6: medium-duty

Medium trucks fall into this set, including some full-size trucks that are used non-commercially. Most of the vehicles in these classes are used commercially, though:

  • Class 4: The GVWR for this class is between 14,001 and 16,000 pounds. The Ford F-450 Super Duty® truck falls into this range, along with box trucks, walk-in trucks and city delivery trucks.
  • Class 5: Trucks between 16,001 and 19,500 pounds fall into this class. A few vehicles are used non-commercially in this class, but primarily this class includes bucket trucks and larger delivery and walk-in trucks.
  • Class 6: What is a Class 6 truck? Medium-duty commercial trucks fall into this class, which covers between 19,501 and 26,000 pounds. School buses are included in this class, as well as beverage and single-axle trucks. This is also the class where the need for a CDL often starts.

Classes 7-8: heavy-duty

Big rigs and other commercial, heavy-duty vehicles are classified starting in this section.

  • Class 7: What is a Class 7 truck? GVWRs range from 26,001 to 33,000 pounds. Most of these vehicles may have three or more axles. Anything from city transit buses to street sweepers and smaller furniture trucks can fall into this category as well.
  • Class 8: What is a Class 8 truck? Big rigs that have GVWRs over 33,000 pounds fall into this category, and can sometimes be referred to as “severe duty” instead of heavy-duty. Cement and dump trucks are present, along with big rigs from manufacturers like Peterbilt and Freightliner.

Class 9: super-heavy/special

While most semitrucks and heavy-duty vehicles are in Class 8, it’s possible for the maximum limit to be set on a case-by-case basis. This is done using the Federal Bridge Gross Weight formula.

  • Class 9: This class includes super-heavy/special-duty trucks, like a five-axle single-trailer truck. It includes all five-axle vehicles consisting of two units, one of which is a tractor or straight truck power unit.

This helps big rigs that are longer and heavier navigate interstate highways. States also allow different exceptions depending on what the Federal Bridge Gross Weight formula determines.

Train on Diesel Technology at UTI

There are many different classifications for vehicles and trucks. One thing that remains true is the importance of keeping these vehicles operating well.

These powerful machines rely on trained diesel technicians to keep them operational so they can perform important tasks that impact our daily lives. You can enroll in the Diesel Technology program offered at UTI and learn how to diagnose and repair problems on a range of large trucks.

In as little as 45 weeks7 you can graduate with the hands-on experience and knowledge it takes to become an entry-level technician in the industry.1

Interested in finding out more? Request more information today!

UTI Campuses That Offer Diesel Mechanic Training

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